This photograph illustrates an example of an arterial
stent in its expanded state. The wire mesh creates a scaffold to maintain a fluid
pathway to maximize the blood flow past an arterial blockage.
Photo courtesy of IntraTherapeutics
High-pressure balloons are commonly used to deploy and post-dilate stents to reduce
the rate of arterial restenosis and acute reclosure following angioplasty. Stents
are metallic scaffolds implanted to support the walls of arteries and other body
cavities. Balloon expandable stents, which are typically machined metal tubes or wire mesh, are crimped over a
balloon and inserted into the area of a blockage after angioplasty. Inflating the
balloon opens the stent, which remains expanded to keep the vessel open. The use
of high-pressure balloons allows the physician to fully expand the stent until it
is in full contact with the arterial wall. The use of a low compliance balloon allows
the added confidence that the stent and the artery will not be over-expanded as
well as the balloon will not dog-bone and over-expand the artery on either end of
the stent. The stent stays in position after the balloon is deflated and removed
from the body. Stents are being used with increasing frequency in association with
angioplasty procedures. This is one of the largest markets for high-pressure balloons
today.
This photograph shows the stent as it is ready to be
inserted into an artery. The stent is at its minimum diameter and crimped over a
balloon. The balloon will be inflated once the physician positions the device in
the desired section of the artery. The expanded stent will then remain in place
permanently.
Photo courtesy of IntraTherapeutics
This photograph shows the stent expanded by the balloon.
The balloon is used to press the stent scaffold against and partially into the arterial
wall. This insures the artery will be fully patent and provide the optimum blood
flow.
Photo courtesy of IntraTherapeutics
PUNCTURE RESISTANT BALLOONS FOR STENT DELIVERY AND STENT RETENTION
Advanced Polymers has developed puncture resistant, high-pressure angioplasty
balloons to increase safety for high pressure angioplasty and stent delivery procedures.
This medical break-through is made possible with the use of a patented coating co-developed
and exclusively licensed by Advanced Polymers.
This patented coating virtually eliminates the chance of an angioplasty balloon
being punctured or damaged during stent delivery and/or post-stent dilatation. Also,
it increases the coefficient of friction between the stent and the balloon surface
and provides excellent stent retention, eliminating movement or slippage during
delivery and deployment. This is a critical issue for high pressure balloon stenting
procedures, as many previously unsaid concerns about stent slippage are coming to
the forefront.
The coating, which can be produced from a variety of polymers depending on the application
(polyurethane is typical and acrylic are typical), is applied to a balloon after
a proprietary surface treatment by dipping it into a liquid form of the chosen polymer,
followed by oven drying. The drying process also allows for cross- – linking of
the coating to occur, which helps to strengthen the coating and provide more durability,
better bond adhesion and increased resistance to solvents and other chemicals.
Advanced Polymers has the capability to produce high pressure angioplasty balloons in a variety
of sizes, configurations, lengths and burst pressures (up to 27 atm/400 psi). Wall
thicknesses typically range from 5 – 50 microns (0.0002" – 0.002"), offering minimal
invasiveness and the smallest possible profile. Some of API’s custom capabilities
and configurations include unlimited tapered angles, varying diameters and tapered
diameters along the length of the balloon. The company recently expanded the available
diameters of its balloons as well, with offerings from 0.5mm to 50mm and an increased
number of standard sizes between 2 – 12 mm. API also has patents and patents pending
for many unique balloon and catheter designs which are available for license.